// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
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// in the documentation and/or other materials provided with the
// distribution.
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//
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#import "LCGPBWireFormat.h"

#import "LCGPBUtilities_PackagePrivate.h"

enum {
  LCGPBWireFormatTagTypeBits = 3,
  LCGPBWireFormatTagTypeMask = 7 /* = (1 << LCGPBWireFormatTagTypeBits) - 1 */,
};

uint32_t LCGPBWireFormatMakeTag(uint32_t fieldNumber, LCGPBWireFormat wireType) {
  return (fieldNumber << LCGPBWireFormatTagTypeBits) | wireType;
}

LCGPBWireFormat LCGPBWireFormatGetTagWireType(uint32_t tag) {
  return (LCGPBWireFormat)(tag & LCGPBWireFormatTagTypeMask);
}

uint32_t LCGPBWireFormatGetTagFieldNumber(uint32_t tag) {
  return LCGPBLogicalRightShift32(tag, LCGPBWireFormatTagTypeBits);
}

BOOL LCGPBWireFormatIsValidTag(uint32_t tag) {
  uint32_t formatBits = (tag & LCGPBWireFormatTagTypeMask);
  // The valid LCGPBWireFormat* values are 0-5, anything else is not a valid tag.
  BOOL result = (formatBits <= 5);
  return result;
}

LCGPBWireFormat LCGPBWireFormatForType(LCGPBDataType type, BOOL isPacked) {
  if (isPacked) {
    return LCGPBWireFormatLengthDelimited;
  }

  static const LCGPBWireFormat format[LCGPBDataType_Count] = {
      LCGPBWireFormatVarint,           // LCGPBDataTypeBool
      LCGPBWireFormatFixed32,          // LCGPBDataTypeFixed32
      LCGPBWireFormatFixed32,          // LCGPBDataTypeSFixed32
      LCGPBWireFormatFixed32,          // LCGPBDataTypeFloat
      LCGPBWireFormatFixed64,          // LCGPBDataTypeFixed64
      LCGPBWireFormatFixed64,          // LCGPBDataTypeSFixed64
      LCGPBWireFormatFixed64,          // LCGPBDataTypeDouble
      LCGPBWireFormatVarint,           // LCGPBDataTypeInt32
      LCGPBWireFormatVarint,           // LCGPBDataTypeInt64
      LCGPBWireFormatVarint,           // LCGPBDataTypeSInt32
      LCGPBWireFormatVarint,           // LCGPBDataTypeSInt64
      LCGPBWireFormatVarint,           // LCGPBDataTypeUInt32
      LCGPBWireFormatVarint,           // LCGPBDataTypeUInt64
      LCGPBWireFormatLengthDelimited,  // LCGPBDataTypeBytes
      LCGPBWireFormatLengthDelimited,  // LCGPBDataTypeString
      LCGPBWireFormatLengthDelimited,  // LCGPBDataTypeMessage
      LCGPBWireFormatStartGroup,       // LCGPBDataTypeGroup
      LCGPBWireFormatVarint            // LCGPBDataTypeEnum
  };
  return format[type];
}
